Stereoselective Synthesis of (+)‐Goniodiol, (+)‐Goniotriol, (–)‐Goniofupyrone, and (+)‐Altholactone Using a Catalytic Asymmetric Hetero‐Diels–Alder/Allylboration Approach

The stereoselective total synthesis of several members of the styryllactone family was achieved efficiently from common intermediate 8 , prepared by a catalytic asymmetric inverse‐electron‐demand hetero‐Diels–Alder/allylboration sequence. The transformation of 8 into α,β‐unsaturated lactone led to the preparation of (+)‐goniodiol ( 1 ) in a reduced number of steps. The epoxidation reaction was used to generate the remaining stereogenic centers on the lactone moiety of 8 , and these intermediates were then elaborated into (+)‐goniotriol ( 2 ), (–)‐goniofupyrone ( 3 ), and (+)‐altholactone ( 4 ) by an isomerization or cyclization step.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)